Principles of Water Sandblasting Paint Rust Removal by High-Pressure Washer

　　Currently, there are two types of processes for treating oxide layer, paint, and rust on metal surfaces: organic chemistry and physics. Chemical treatment is mainly dominated by pickling and passivation, which involves exothermic reactions occurring during the passivation of stainless steel, leading to etching and achieving the treatment purpose. However, the disadvantage of organic chemistry treatment is that it takes up a lot of space, the processing technology is complicated, the air pollution is relatively severe, and the difficulty of wastewater treatment is high, requiring a considerable investment of funds.

　　The physics approach can be roughly divided into several categories, such as shot blasting rust removal, gas sandblasting treatment, and high-pressure water technology. Gas sandblasting treatment is prohibited due to the large amount of dust and severe environmental pollution. High-pressure water technology can be further divided into pure water treatment and high-pressure water sandblasting treatment. In terms of high-pressure washer water spray technology, if pure high-pressure water is used for paint removal and rust prevention treatment, working pressure of equipment must be very high, usually around 2000KG, with an output power of about 90KW, and a large total flow rate. In contrast, high-pressure water sandblasting treatment has a lower working pressure and output power, higher efficiency, and cost savings. Usually, a 500KG device with a sandblasting treatment module can achieve the actual effect of paint removal, rust prevention treatment, and removal of oxide layer.

　　The basic principle of paint and rust removal by high-pressure washer water sandblasting treatment is that high-pressure spraying generates high-pressure water, which is sprayed from sandblasting treatment head through a high-pressure pipeline and creates air pressure in the sandblasting treatment chamber. The reserved sand enters the sand tube, and broken stones in the sand tube move into sandblasting treatment chamber due to pressure difference, and mix with high-pressure water in sandblasting treatment chamber, accelerating their movement and quickly spraying out to hit the surface of steel structure. This process produces necessary drilling and cutting effects, causing non-inherent stains, plant oils and greases, floating rust, and air oxide skin to fall off steel structure in an instant, exposing the metallic texture of stainless steel and achieving the desired surface effect.